Non-electronic multifuel engines basically don't run good on anything, but run so-so on everything.

As for the more modern versions, the Leaopard 2's engine for example varies injection timing, injection pressure, and boost to achieve not-optimum-but-good running on nearly anything that is liquid and burns. We even ran one on 160 proof rum once just for kicks, and it still put out 1300ish horsepower.

_________________

SMoAF wrote:

We all ended up moving in together at one point, and I paid our rent in guns.

Vicarious_Lee wrote:

No one on ZS worth their membership would be in a frozen forest, alone, without being loaded out like they've got Les Fucking Stroud himself in their enormous and ergonomic backpack.

seems to me like the addition or modification of a fuel density compensator on regular deisels could make it run on more whacky things. right?

In theory yes. However in practice, I'm sure there is more to it than the compensator. Most diesels run well enough on waste motor oil, kerosene, marine diesel, and veg oil. If you want to get much crazier than that, the best advice i can give you is to check in at steel soldiers for info on the FDC and try some of the alt fuel forums.

seems to me like the addition or modification of a fuel density compensator on regular deisels could make it run on more whacky things. right?

In theory yes. However in practice, I'm sure there is more to it than the compensator. Most diesels run well enough on waste motor oil, kerosene, marine diesel, and veg oil. If you want to get much crazier than that, the best advice i can give you is to check in at steel soldiers for info on the FDC and try some of the alt fuel forums.

Pretty much all the FDC does is make sure you have the same power no matter what fuel you run. It also affects fuel consumption, as some fuels need more or less to make the same power as diesel. A multi-fuel diesel can run all the same fuels without the FDC. However, power levels will vary. IIRC, what makes a multi-fuel able to run so many fuels with ease is an absurdly high compression ratio (even for diesels) at 25:1 to 27:1.

IIRC, what makes a multi-fuel able to run so many fuels with ease is an absurdly high compression ratio (even for diesels) at 25:1 to 27:1.

That's one of the aspects, yes. The best engines though have a controlled compression ratio though, to prevent extreme cases of knocking, as will happen when using ethanol. Basically, the supercharger uses a "stepless" gearbox to achieve more or less compression, resulting in a lower or higher oxygen density in the cylinder, and thus lowering or raising the knock point. The real art is in getting the engine to sense knocking, and adjusting the boost accordingly.

That being said, EMP-proof ECUs are extremely expensive. That, and I don't believe they are sold on the civilian market.

_________________

SMoAF wrote:

We all ended up moving in together at one point, and I paid our rent in guns.

Vicarious_Lee wrote:

No one on ZS worth their membership would be in a frozen forest, alone, without being loaded out like they've got Les Fucking Stroud himself in their enormous and ergonomic backpack.

IIRC, what makes a multi-fuel able to run so many fuels with ease is an absurdly high compression ratio (even for diesels) at 25:1 to 27:1.

That's one of the aspects, yes. The best engines though have a controlled compression ratio though, to prevent extreme cases of knocking, as will happen when using ethanol. Basically, the supercharger uses a "stepless" gearbox to achieve more or less compression, resulting in a lower or higher oxygen density in the cylinder, and thus lowering or raising the knock point. The real art is in getting the engine to sense knocking, and adjusting the boost accordingly.

That being said, EMP-proof ECUs are extremely expensive. That, and I don't believe they are sold on the civilian market.

I think you're referring to more modern multi-fuel diesels. The engines in the Deuce and a Half trucks are VERY simplified. There's no electronics that are required on the truck other than the starter solenoid. Everything else is controlled mechanically.

Okay, so does that mean you could easily EMP-proof a deuce? If the glowplugs were shot, could you just heat the head with a torch like an old tractor, and then turn it over somehow? Old double-decker buses sometimes have crank-start couplings even though those old diesels are so big the heads come in two pieces just so you can lift it off. I can't imagine what they'd use to turn it, though. Any experiences starting one one without a battery?

You could probably pull start a Duece with a couple of mules or a slight downward incline. The multifuel engine starts relatively easy compared to anything else I've tried. Otherwise, the truck should run and operate fine. It doesn't even NEED the in tank fuel pump to run. The injection pump has enough pull that it can fuel itself, albeit not as efficiently.

I assume you're referring to the M35A2's that are all over the surplus market.

They have a very simple electrical system, they don't even have fuseboxes in them. No electronics to worry about.

As to how well they run on other fuels, my old Reserve unit found out the hard way that they DO need to be manually adjusted for more extreme changes in fuel. Somehow all the Deuces and 5-tons in the convoy got fueled with gasoline instead of diesel on the way to Ft. Indiantown Gap. The 5-ton's didn't last too long before they started dying off on the side of the road. The deuces went a lot longer, but eventually they choked and died as well on the gasoline. Or at least, so I was told. Thank god I didn't have to go on that trip with them.

-Hans

_________________"This does not mean, however, that we are unaware of the true meaning of the term 'security.'To us, the term has broad meaning. It rests in the physical force embodied as it is in the ships and their base, but also in intellectual factors among which Intelligence plays an outstanding role."- Captain Ellis M. Zacaraias, USN

I assume you're referring to the M35A2's that are all over the surplus market.

They have a very simple electrical system, they don't even have fuseboxes in them. No electronics to worry about.

As to how well they run on other fuels, my old Reserve unit found out the hard way that they DO need to be manually adjusted for more extreme changes in fuel. Somehow all the Deuces and 5-tons in the convoy got fueled with gasoline instead of diesel on the way to Ft. Indiantown Gap. The 5-ton's didn't last too long before they started dying off on the side of the road. The deuces went a lot longer, but eventually they choked and died as well on the gasoline. Or at least, so I was told. Thank god I didn't have to go on that trip with them.

-Hans

I've heard of SS (steel soldier) members running on gasoline for a while. I don't know how long for sure, but I know the truck doesn't run as good.

Um...you are not supposed to run the Deuce on straight gas. You are supposed to only use gas when mixed with oil.

Regarding how they run, I have one from GL with 12,000 miles from a National Guard unit.I bought it cheap and it runs great.

As in, turn the power switch and push the button. As soon as the starter spins the engine fires up.In colder weather I just give it 5 minutes to warm up and smooth out.Mine runs very smooth, idles nicely and pulls cleanly with plenty of power.It does 50 mph easily and tops out at 62-65mph with 9.00x20 NDTs.

I have only run mine on diesel and an oil/diesel mix, so cannot comment further.

I think if you find a truck in excellent running condition you will have no issues.I love mine and drive it all the time, with zero issues of any kind.

Here's my next one: I often hear of people pulling the diffs off of these things and using them on their 4x4s. Are they all interchangeable, in other words, if I bob a deuce do I then have a spare diff for the rear?

I haven't looked too close at the PTO... I know the pto winch has a teeny little crankshaft but the one on the back comes out of... a transfer case? My real question is, can I put a duece diff under my 4x4 and then rig up a PTO on my truck?

Here's my next one: I often hear of people pulling the diffs off of these things and using them on their 4x4s. Are they all interchangeable, in other words, if I bob a deuce do I then have a spare diff for the rear?

I haven't looked too close at the PTO... I know the pto winch has a teeny little crankshaft but the one on the back comes out of... a transfer case? My real question is, can I put a duece diff under my 4x4 and then rig up a PTO on my truck?

Short answer, Yes and yes. First is a simple plug and play. The second option will require an adapter to get the trans to fit whatever engine you have. After you fit the trans to your engine, you just have to mate up a winch (or whatever) to the PTO shaft.

It sounds like, if I want a truck with that much beef underneath, I should just start with a deuce and save myself the hassle. Sure would like a PTO on the ole Blazer though.

Older Np-205 transfer cases have the provision for a PTO. You just have to find an application that'll fit that case. They're normally up on EBay all the time. At least when I was building my Blazer a few years back I could find a PTO setup for the 205 just about any time I wanted.

I don't know if anyone here knows the answer, but I was always curious about mixing fuels in a deuce. Lets say you had a tank half full of straight diesel, then poured in some used motor oil, next day you have some veg oil/kerosene/alcohol. Can any mixture of combustible liquids be used or do you have to be careful about mixing?

I don't know if anyone here knows the answer, but I was always curious about mixing fuels in a deuce. Lets say you had a tank half full of straight diesel, then poured in some used motor oil, next day you have some veg oil/kerosene/alcohol. Can any mixture of combustible liquids be used or do you have to be careful about mixing?

You gotta find what works. The intended application was oh-shit-we-gotta-go-pour-whatever-innit but your non-emergency user will be interested in running it well and keeping it clean. As mentioned earlier straight gasoline will screw it up, and I hear certain other things will gum up the system. One person here said they were running 80% used oil. The rule is "add diesel until it runs".

I'm interested if anyone's ever tried petroleum jelly, we're sittin' on 8000 gallons of vaseline here* and I wonder if you could pre-heat it to a liquid and run it in the multifuel...

*yes, we already had the wrestling party. The 8000 gallons are what's left over after THAT.

_________________When the only tool you have is a hammer, every problem starts looking like a hippie.

I ran about 80% FMO (filtered motor oil) from Louisville to St Louis. With a non-turbo truck running 55-60mph on the interstate I got about 8.5mpg. You could probably run petro jelly, but you need to cut it with something. Try diluting it with diesel fuel or paint thinner.